`pytransform3d.transformations`.check_dual_quaternion¶

pytransform3d.transformations.check_dual_quaternion(dq, unit=True)[source]¶

Input validation of dual quaternion representation.

See http://web.cs.iastate.edu/~cs577/handouts/dual-quaternion.pdf

A dual quaternion is defined as

$\boldsymbol{\sigma} = \boldsymbol{p} + \epsilon \boldsymbol{q},$

where $\boldsymbol{p}$ and $\boldsymbol{q}$ are both quaternions and $\epsilon$ is the dual unit with $\epsilon^2 = 0$ . The first quaternion is also called the real part and the second quaternion is called the dual part.

Parameters:

dqarray-like, shape (8,): Dual quaternion to represent transform: (pw, px, py, pz, qw, qx, qy, qz)
unitbool, optional (default: True): Normalize the dual quaternion so that it is a unit dual quaternion. A unit dual quaternion has the properties $p_w^2 + p_x^2 + p_y^2 + p_z^2 = 1$ and $p_w q_w + p_x q_x + p_y q_y + p_z q_z = 0$ .

Returns:

dqarray, shape (8,): Unit dual quaternion to represent transform: (pw, px, py, pz, qw, qx, qy, qz)

Raises:

ValueError: If input is invalid

pytransform3d.transformations.check_dual_quaternion¶

`pytransform3d.transformations`.check_dual_quaternion¶